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Tutorial

In this lesson, you're going to get a little bit more into the biological aspects of psychology, and explain exactly how things like your brain and nervous system work to create our minds and behavior. Specifically you will focus on:

Neurons

1. NEURONS

A neuron is the basic cellular building block of our brain and your nervous system. It's the thing within your body that acts as the messenger, and sends information to and from the brain and other parts of our body. It allows certain messages to be sent, so you can move and act in the ways that we intend.

This is different from a nerve, which you may have heard of. Nerves are actually groups of neurons that transmit information throughout the rest of the body. In your arms, in your legs, we have nerves, which are just bundles of these neurons that are called together.

Nerves

Cord or cable-like bundles of axons which carry messages to and from the body and brain.

A neuron has certain special structures that make it different from other cells, but allow it to function as this messenger within your body.

First, you have your soma, or your cell body. This is the central area of the neuron that makes it just like other cells. It contains all the different structures that different cells in your bodies contain. Things like your nucleus, with the DNA inside of it and all the different sorts of things that other cells have. So the important thing to remember is the soma is your cell body; the center of the neuron.

Soma

The central part of the neuron, which contains all the basic parts of a cell (nucleus, mitochondria, etc.); the cell body.

Outside of that, you have these little branching, tree-like structures, which you call dendrites. Which actually comes from the Greek word, "dendri," for tree.

Dendrites

The part of the neuron that branches out into many smaller parts, which receive signals from other neurons.

An easy way to remember the term dendrites is that it looks like a tree and it comes from the word for "tree."

These aspects of the neuron, that branch off into lots of smaller parts, receive information from other neurons. This is the receiving section of the neuron. It takes in messages that other cells and neurons send to it, and then transmits it to other cells outside of that.

Extending out from the cell body is this long tail-like structure, which we called the axon of the cell. While the dendrite's job is to receive information from other neurons, the axon's job is to transmit that information to other neurons that would be attached to this neuron.

It starts at the cell body, in the area is called the axon hillock, and extends all the way to a button-like structure at the end, which is called the axon terminal.

Axon

The long tail-like structure that comes off of the cell body and sends signals along the cell and out to other cells.

When said this is a long tail-like structure that can vary wildly. Some axons can be only 1/10 of a millimeter long, but some of them can extend up to a meter long, especially in other parts of our body. The axon essentially transmits an electrical impulse from within the cell, starting at the dendrites and the cell body, all the way across this tail, and then out to other neurons that might be attached to it.

It's sort of like an electrical wire, and just like with an electrical wire, you can improve the transmission of that electrical signal by insulating it. By putting something around that axon to make the message transmit faster. This is true in certain neurons within the brain itself; they have what's called a myelin sheath. The myelin sheath is this insulating layer of fat, which is called glial cells, which wraps around the axon, and makes that electrical impulse shoot faster through the axon, and then down to other neurons that might be attached. And because this myelin sheath is made of fat, it actually makes the neuron look like it's white, which is why we say in the brain, that there's white matter, which is the myelinated neurons within the brain, and then gray matter which is the non-myelinated ones.

Myelin Sheath

A layer of fatty cells that covers some neurons' axons and allows them to transmit information faster in the brain.

This tutorial discussed how your brain and nervous system work to create our minds and behavior, specifically focusing on neurons. A neuron is the basic cellular building block of our brain and your nervous system

Good luck!

Source: This work is adapted from Sophia author Erick Taggart.

TERMS TO KNOW

Soma

The central part of the neuron, which contains all the basic parts of a cell (nucleus, mitochondria, etc.); the cell body.

Dendrites

The part of the neuron that branches out into many smaller parts, which receive signals from other neurons.

Axon

The long tail-like structure that comes off of the cell body and sends signals along the cell and out to other cells.

Myelin Sheath

A layer of fatty cells that covers some neurons' axons and allows them to transmit information faster in the brain.

Nerves

Cord or cable-like bundles of axons which carry messages to and from the body and brain.